Flex pump



A. C. MAMO FLEX PUMP Jan. 19, 1965 3 Sheets-Sheet l Filed Dec. 26, 1962 m. 1T. n 6 w 1 A. C. MAMO FLEX PUMP Jan. 19, 1965 5 Sheets-Sheet 2 Filed Dec. 26, 1962 jnz/eni'of GnZ /wny C Mama NKI N A. C. MAMO FLEX PUMP Jan. 19, 1965 s Sheets-Sheet 5 Filed Dec. 26, 1962 3,166,017 FLEX PUMP AnthonyC. Mame, Des Plaines, 111., assignor to Borg- Warner Corporation, Chicago, 111., a corporation of Illinois Filed Dec. 26, 1962, Ser. No. 247,il7

14 Claims. (Cl. 103-123) The present invention relates to a rotary pump and more particularly to a pump of this type wherein the rotor comprises a generally elliptical bearing.

Generally speaking, the elliptical bearing at its'rnajo axis provides lobes which are comparable to the vanes in a conventional type vane pump. This elliptical bearing may also be termed a lobed bearing, whichmay be pro vided with one or a multiplicity of lobes The outer race or member of the elliptical bearing is nonelastic and flexible, and themajor axis of the elliptical bearing is of j a geometry such that the outer race will make contact with the inner periphery of a cavity at two opposing areas.

I As the rotor turns the inner race rolls on the rollers of the bearing thereby causing the outer race, at its lobe areas, to contact the inner periphery of the housing in a progressive movement around its periphery as hereinafter more fully explained;

It is therefore an important object of the present invention to provide an improved rotary pump wherein the driven member of the rotor moves at a substantially lower velocity than the drive member.

It. is also an important object of the present invention to provide an improved rotary pump which is hydraulically and mechanically balanced and wherein the frictional losses are greatly reduced.

It is another important object of the present invention to provide an improved positive displacement pump employing a lobedbearing.

The invention consists of the novel construction, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects and such other objects as will be apparent from the following description of preferred forms of the invention, illustrated with reference to the accompanying drawings, wherein:

FIGURE 1 is an elevational view of a rotary pump according to the present invention with the end plate removed showing the components therein;

FIGURE 2 is a cross section taken on line 2-2 of FIGURE 1;

FIGURE 3 is a cross section taken on line 33 of FIGURE 1;

FIGURE 4 is a cross section taken on line 4-4 of FIGURE 1;

FIGURE 5 is a cross section fragmentary view of the bearing and rotor within the housing showing a fluid sealing means;

FIGURE 6 is a fragmentary view taken on line 6-45 of FIGURE 5;

FIGURE 7 is a fragmentary view showing a modification of the rotor, FIGURE 1, wherein a segment of the rotor is removed at the minor diameter instead of the major diameter;

FIGURE 8 is a fragmentary view showing a modified form of the housing in FIGURE 1, comprising a flexible ring Within the inner periphery of the housing;

FIGURE 9 is a sectional view in the direction indicated by line 9-9 of FIGURE 8; and

FIGURE 10 is a fragmentary elevational view of a modified form of the present invention with the end plate removed.

Like characters of reference designate like parts on the several views.

Referring now to FIGURE 1, numeral 10 designates a suitable housing having a cylindrical cavity 11 therein. A

drive shaft 12 is centrally journaled within the cylindrical cavity 11 and has a generally elliptical driving cam, or lobed rotor 13 connected thereto by means of a pin .14. A roller bearing 15 comprising flexible outer and inner races 16 and'17, respectively, having rollers 18 therebetween, is force mounted over the elliptical rotor 13 there 1 by becoming generally elliptical in shape. The major axis of the outer race 16 provides lobes orcontact areas 19 and 20 which are in fluid sealing engagement with the inner periphery or peripheral wall 21 of the cylindrical cavity 11. The minor axis of the elliptical bearing 15 provides Working areas 22 and 23 between the outer race 16 and the inner periphery 21 of the cylindrical cavity 11.

The generally elliptical rotor 13 has flattened areas 24 and 25 at the outer ends of the lobes. These flattened areas are provided so as to eliminate the necessity for maintaining a close dimensional control of the bearing 15 and the cylindrical cavity 11. This is so, because with segments removed from the major axis of the rotor 13,

' which. produce the flattened areas 24 and 25, the flexibility of the bearing 15 will accommodateitself with respect to tolerances.

Vanes 26 and 27 operable in slots 28 and 29, respectively, are provided at opposite ends of the housing 10. The outer ends of the vanes 26 and 27 are provided with cylindrical heads 30 and 31, respectively, operable Within bores 32 and 33, respectively, Which extend coaxially with the slots 28 and 29. Within the cylindrical bores 32 and 33, springs'34 and 35, respectively, are biased between the cylindrical heads 30 and 31 and plates 36 and 37, respectively, which are secured to the outer ends of the housing by two sets of bolts 38 and 39. A suction port 40 and a pressure port 41 which are in communication with the cylindrical cavity 11 are positioned on opposite sides of the vane 26 and comparable suction and pressure ports 42 and 43, respectively, are positioned on opposite sides of the vane 27.

an annular pressure plate 48 having an annular protru-. sion 49 at its inner'face thereby providing a pair of annular chambers 50 and 51 within the annular recess 47. The end plate45 is also provided with'a port 52 in fluid communication between the annularchambers 49 and 50, and the pressure port 41 by means of a conduit 53 whereby pressure is provided which urges the annular pressure plate 48 against the adjacent face of the roller bearing 15 which, in turn, causes the opposite face of the bearing 15 to move into fluid sealing engagement with the side wall 54 of the cylindrical cavity 11. In order to prevent fluid loss the annular pressure'plate 48 is provided with fluid seals 55 and 56, such as 0 rings, at its inner and outer peripheries. drive shaft 12 are provided on opposite faces of the rotor 13 and are held from rotational movement by right angle Patented J an. 19, 1965 Spacer washers 57 and 58 mounted on the shown in FIGURE 7. This modification-of the vanes and 7 their associated components,.comprises positioningthem.

at an acute angle and :in a. direction against rotational movement of the rotor 13 which virtually eliminatesthe sliding movement between the vanes and the outer race 16. A modification of the cylindrical cavity 11 as shown in FIGURE 8 is another means of elirninating the neces'-. sity for maintaining close dimensional control. with respect to the bearing 15, which comprises an annular yieldable wall 65 spaced from. the inner periphery ofth'e cylin- '7 sealing against fluid loss.

tolerances in manufacturing the rotor 75 is avoided. *'The f pin 14, of course, is not required. i '10 drical cavity 11 by protrusions 66 and 67 thereon one each opposite the'vane 26. The annular yieldable .walld .is

of a; width equal to that of the cylindrical cavity 11 except I at the area of the vane where a widened area 68 is prov vided having a rectangulanopening 69 therethrough to accommodate ,the vane 26 and the suction and pressure port's40 and '41, respectively. In order to accommodate the widenedarea 68, recesses 76 and 71are. provided at the innerfaces of the cylindrical cavity 11 and the fend plate 45. Y

- The opposite portion-of the annular yieldable wall .65

a'ndthe adjacent Walls of the cylindrical cavity 11 and the annular pressure plate 48 are similarly fashioned.

A modified form of the invention, FIGURE 10, utilizes a journal bearing '72 comprising an elliptical yieldable journal 73 and a flexible bearing part 74'mounted over a generally rectangular rotor' v 75 having cam shaped ends or lobes 76 and 77. a V

In operation, the rotor 13 which is moving counterclockwise as. indicated by the arrow, causes the outer race 16, which is in contact with the innerperiphery'of the cylindrical cavity 11 at areas at both ends of its major axis, to progressively contact the inner periphery of the cylindrical cavity in very limited fluid sealing engagement which causes the. fluid in the working areas 22 .and 23, forward of the vanes 26 and 27, respectively, to move into,

thepressure ports 41 and 43,. respectively. Simultaneously, the working areas 22 and 23 that are on the opposite sides of the vanes 26 and 27, respectively, are being provided with fluid from the suction ports and 42, 're

spectively, which provides fluid for the succeeding pump-.

ing impulses. It is, therefore, apparent that with two pressure ports and two suction ports two' pumping int-- pulses are provided with each revolution of the. rotor 13.

It is to be understood that a flex pump according to the present invention would be operable with but one pressure port and one'suction port, but this would produce an unbalance.

It should also be noted that with the use of the elliptical bearing 15 according to the present invention the outer race 16 has avery low r.p.m. with respectzto the input. Actually, its sliding velocity is reduced by approxb mounted over a' reduced 12. The. reduced diameter 77 is providedjwith flatsurthe inner periphery of the journal bearing 72 for effective Also the necessity for close While this. invention has been describedin connection with certain specific embodiments thereof, it is to be understood that is by way of illustration and not by way of limitation and the scope of this invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit. I' claim;

1. Av rotary'pump comprising; a casing'having a hot I I thereindefining a cylindrical cavity provided with a pcripheral wall and side walls; a multiple'lobed rotor jo n naled in said casing "coaxially within said cylindrical cavity; a'b earing having. an inner member and a nonelas -tic. flexible outer 'membermounted over said multiple lobed rotor thereby'providing. multiple lobes on said bearing equal in number to the number'of lobes on said multiple lobed rotonsaid multiple lobes on; s'aidbearing extending radially to a degree such as to be in fluid seal-v ing contact with said peripheral wall thus providing work-' ing areas in the area encompassed bysaid multiple lobes on said bearing, the adjacent portion ofv said inner periphery,- the adjacent portion of the outer face of said outer nonelastic flexible member and-the adjacent portions of said side walls, the said outer nonelastic flexible member being of a width to be in fluid sealing contact with said side walls, the said inner member being in rotatable en gagement with said rotor which causes said outer non,- elastic flexiblemember to flex as said inner member rotates with respect to said outer nonelastic flexible member rolling progressively on said peripheral wall with scant sliding thereon; a vane reciprocally mounted in said casing extending through said peripheral wall towards said outer nonelastic flexible member and in'fluid sealing I engagement-therewith; a suction port in said peripheral wall on one side of said vane in fluid communication with said cylindrical cavity; and a pressure port in said peripheral wall on the opposite side of said vane in fluid communication with said cylindrical cavity.

2. A rotary pump according to claim 1 wherein the said nonelastic flexible outer member is encompassed by a U-shaped ring having radially inwardly extending segments to thereby provide more effective sealing against fluid loss, the said nonelastic flexible outer member being imately percent. at the sides and nearly at the.

outer periphery for the reason that the outer race .16 is required to slide only to the extent of the dilferential between the inner periphery of the cylindrical cavity and the'outer periphery of race 16. V

In the interestof maximum efliciency, it is recognized that port sizes should be as large as possible. However, if the port sizepis beyond a certain minimum, a point willbe reached where intercommunication between suction and pressure ports'will occur for a small'fraction of time.

This, however, can be eliminated. by the use of the U- shaped flat flexible spring 44' which will substantially eliminate the intercommunication referredto because of the contacts between the ends of the spring'with the' outer race 16 as indicated by the dotted line in FIGURE 1. In operation the modified form, FIGURE 10, is similar operationally, the difference residing in the substitution of a v journal bearingfor a rollerb'earing or a ball bearing, notshown, it being understood that a ball bearing may be used without departing from the spirit of the present invention.

With the use of the journal bearing 72 the generally rectangular rotor 75 may consist of two parts 75a and n reduced in width to accommodate said U-shaped ring with its inwardly extending segments. e

3. A rotary pump according to claim 1 wherein the said exhaust port is provided with a U-shaped flat flexible spring of a width substantially that of said cavity, the far end of which extends beyond the said peripheral wall to thereby prevent fluid intercommunication between the said pressure and suction ports when they exceed the maximum size permissible to prevent intercommunication.

4. A rotary pump according to claim 1 wherein the said peripheral wall comprises a semi-rigid annular ring 7 thereby providing extensibility of said inner peripheral wall to accommodate lack of adequate tolerance atthe major axis of the bearing in assembling.

5.. A rotary pump according to claim 1 wherein one of said side walls comprises an annular pressure plate provided with fluid means for urging said pressure plate into sealing engagement with the said nonelastic flexible outer member.

6. A rotary pump according to claim 1 wherein the said inner member comprises a yieldable journal.

7. A rotary ,pump according to claim 1 wherein the said vane is positioned at an acute angle and in a direction against rotational movement of the said rotor 3 thereby virtually eliminating the sliding movement be ween the said vane and the said noneiastic flexible outer member.

8. A rotary pump according to claim 1 comprising a ball bearing having a nonelastic flexible outer member.

9. A rotary pump according to claim 1 wherein the said multiple lobed rotor is elliptical in shape and wherein a second vane corresponding to said vane and substantially opposite thereof, and a second suction port and a second pressure port comparable to said suction and pressure ports respectively are provided on opposite sides or said second vane.

10. A rotary pump according to claim 9 wherein said inner member is elliptical in shape to correspondto the elliptical shape of said rotor and wherein a comparable second vane, a comparable second suction port, and a comparable second pressure port are provided in the easing substantiaiy opposite the said vane, the said suction and pressure ports respectively.

11. A rotary pump according to claim 9 wherein a said inner member is semi-rigid thereby conforming to the shape of said elliptical rotor when mounted thereover.

12. A rotary pump according to claim 9 wherein the said elliptical rotor is provided with flattened ends at its major diameter to thereby accommodate the mounting of said bearing in the event of a minus tolerance.

13. A rotary pump according to claim 9 wherein the said elliptical rotor is provided with flattened ends at its minor diameter to thereby accommodate the mounting of said bearing over said motor in the event of a minus tolerance.

14. A rotary pump comprising: a casing provided with a bore therein defining a cylindrical cavity having a peripheral wall and side walls at right angles thereto; a multiple lobed rotor journaled in said casing coaxially within said cylindrical cavity; a roller bearing comprising an outer nonelastic flexible member and an inner member mounted over said multiple lobed rotor,

the said outer nonelastic flexible member thereby having multiple lobes which extend outwardly to a degree such as to be in iluid sealing contact with said peripheral wall, thus providing working areas in the area encompassed by said multiple lobes on said outer nonelastic flexible member, the adjacent portion of said peripheral wall, the adjacent portion of the outer face of said outer nonelastic flexible member and the adjacent portion of said side walls, the said outer nonelastic flexible member being of a width to be in fluid sealing contact with said side walls, the said inner member being in rotatable engagement with said rotor which causes said outer flexible member to roll on the rollers of said roller bearing and flex as it progresses on said peripheral wall with scant sliding thereon; and a vane reciprocally mounted in said casing extending through said peripheral Wall toward said outer flexible member and in fluid sealing engagement therewith; a suction port in said peripheral wall on one side of said vane in fluid communication with said cylindrical cavity; and a pressure port in said peripheral wall on the opposite side of said vane in fluid communication with said cylindrical cavity.

References Cited in the file of this patent V UNITED STATES PATENTS 444,834 Hayes Jan. 20, 1891 1,890,571 Dubrovin Dec. 13, 1932 2,050,473 Steinmann Aug. 11, 1936 2,373,457 Chisholm Apr. 10, 1945 2,407,753 Wallgren Sept. 17, 1946 2,451,603 Barker Oct. 19, 1948 2,848,952 Wakem-an Aug. 26, 1958 2,957,428 Meyer et a1. Oct. 25, 1960 FOREIGN PATENTS r 692,928 Great Britain June 17, 1958 276,365 Italy July 23, 1930 133,801 7 Sweden Dec. 4, 1951 

1. A ROTARY PUMP COMPRISING: A CASING HAVING A BORE THEREIN DEFINING A CYLINDRICAL CAVITY PROVIDED WITH A PERIPHERAL WALL AND SIDE WALLS; A MULTIPLE LOBED ROTOR JOURNALED IN SAID CASING COAXIALLY WITHIN SAID CYLINDRICAL CAVITY; A BEARING HAVING AN INNER MEMBER AND A NONELASTIC FLEXIBLE OUTER MEMBER MOUNTED OVER SAID MULTIPLE LODED ROTOR THEREBY PROVIDING MULTIPLE LOBES ON SAID BEARING EQUAL IN NUMBER TO THE NUMBER OF LOBES ON SAID MULTIPLE LOBED ROTOR, SAID MULTIPLE LOBES ON SAID BEARING EXTENDING RADIALLY TO A DEGREE SUCH AS TO BE IN FLUID SEALING CONTACT WITH SAID PERIPHERAL WALL THUS PROVIDING WORKING AREAS IN THE AREAS ENCOMPASSED BY SAID MULTIPLE LOBES ON SAID BEARING, THE ADJACENT PORTION OF SAID INNER PERIPHERY, THE ADJACENT PORTION OF THE OUTER FACE OF SAID OUTER NONELASTIC FLEXIBLE MEMBER AND THE ADJACENT PORTIONS OF SAID SIDE WALLS, THE SAID OUTER NONELASTIC FLEXIBLE MEMBER BEING OF A WIDTH TO BE IN FLUID SEALING CONTACT WITH SAID SIDE WALLS, THE SAID INNER MEMBER BEING IN ROTATABLE ENGAGEMENT WITH SAID ROTOR WHICH CAUSES SAID OUTER NONELASTIC FLEXIBLE MEMBER TO FLEX AS SAID INNER MEMBER ROTATES WITH RESPECT TO SAID OUTER NONELASTIC FLEXIBLE MEMBER ROLLING PROGRESSIVELY ON SAID PERIPHERAL WALL WITH SCANT SLIDING THEREON; A VANE RECIPROCALLY MOUNTED IN SAID CASING EXTENDING THROUGH SAID PERIPHERAL WALL TOWARDS SAID OUTER NONELASTIC FLEXIBLE MEMBER AND IN FLUID SEALING ENGAGEMENT THEREWITH; A SUCTION PORT IN SAID PERIPHERAL WALL ON ONE SIDE OF SAID VANE IN FLUID COMMUNICATION WITH SAID CYLINDRICAL CAVITY; AND A PRESSURE PORT IN SAID PERIPHEERAL WALL ON THE OPPOSITE SIDE OF SAID VANE IN FLUID COMMUNICATION WITH SAID CYLINDRICAL CAVITY. 